There is currently a huge economic fear of deflation. This fear is basically built on the following three pillars.
First, that deflation would result in consumers delaying any purchases of goods and services as they will be cheaper tomorrow than they are today. Secondly, that debt will become unsustainable for borrowers as the debt will not be inflated away, creating defaults, recession and further deflation. And finally, that monetary policy will no longer be effective as interest rates have hit the zero bound, once again resulting in a deflationary spiral.
The first point is an example of economic theory not translating into economic practice. Individuals are not perfectly rational on timing when to buy discretionary goods. For example, people will borrow at a high interest rate to consume goods now that they could consume later at a cheaper price. One can also see how individuals constantly purchase discretionary consumer goods that are going to be cheaper and better quality in the future (for example: computers, phones, and televisions). Therefore the argument that deflation stops purchases does not hold up in the real world.
The second point that borrowers will go bust is also wrong. We have had a huge period of disinflation over the last 30 years in the G7 due to technological advances and globalisation. Yet individuals and corporates have not defaulted as their future earnings disappointed due to lower than expected inflation.
The third point that monetary policy becomes unworkable with negative inflation is harder to explore, as there are few recent real world examples. In a deflationary world, real interest rates will likely be positive which would limit the stimulatory effects of monetary policy. This is problematic, as monetary policy loses its potency at both the zero bound and if inflation is very high. This makes the job of targeting a particular inflation rate (normally 2%) much more difficult.
What should the central bank do if there is naturally low deflation, perhaps due to technological progress and globalisation? One response could be to head this off by running very loose monetary policy to stop the economy experiencing deflation, meaning the central bank would attempt to move GDP growth up from trend to hit an inflation goal. Consequences of this loose monetary policy may include a large increase in investment or an overly tight labour market. Such a policy stance would have dangers in itself, as we saw post 2001. Interest rates that were too low contributed to a credit bubble that exploded in 2008.
Price levels need to adjust relative to each other to allow the marketplace to move resources, innovate, and attempt to allocate labour and capital efficiently. We are used to this happening in a positive inflation world. If naturally good deflation is being generated maybe authorities should welcome a world of zero inflation or deflation if it is accompanied by acceptable economic growth. Central banks need to take into account real world inflationary and deflationary trends that are not a monetary phenomenon and set their policies around that. Central bankers should be as relaxed undershooting their inflation target as they are about overshooting.
Under certain circumstances central banks should be prepared to permit deflation. This includes an environment with a naturally deflating price level and acceptable economic growth. By accepting deflation, central banks may generate a more stable and efficient economic outcome in the long run.